Scyld performance problems

Not specifically related to Scyld's linpack settings, I found that the
defaults for xhpl were set too small to be interesting at all. I had to
bump 'N' way up (in my case 42000) to get anything relating to numbers
that I would have expected. Also, you need to set 'P' and 'Q' correctly
to actually use all the cpus.
-Dean